1. Field of the Invention
The present invention relates to a mark inspecting system for inspecting marks formed on a tire. The term, "tire" is used herein to signify both a finished tire and a semifinished tire still in process.
2. Description of the Related Art
Marks including a uniformity mark indicating acceptable uniformity determined by the measurement of a tire and a balance mark indicating a lightest portion of the tire are marked on the side wall of the tire by a marking device. Operators inspect tires visually to see if the marks are formed properly. However different operators give different decisions, and the visual inspection of the marks by the operators takes much time and has been an obstacle to the perfect automation of a inspection line for labor saving.
An automatic mark inspecting system is disclosed in JP-A No. 6-84002. This prior art automatic mark inspecting system places a tire provided with a mark on a rotating inspection table, rotates the rotating inspection table supporting the tire, and photographs the mark formed on the tire by a camera for inspection. This automatic mark inspecting system needs the special rotating inspection table and a conveying mechanism for conveying the tire onto the rotating inspection table. Therefore, this known automatic mark inspecting system needs great equipment and operating costs, and a large space for installation. Thus, this known automatic mark inspecting system is low in space efficiency. Furthermore, this known mark inspecting system needs to position the tire on the rotating table for photographing by a camera, which requires a special positioning device.
A tire marked by the marking device is conveyed to a mark inspecting process and marks marked on the tire are inspected some time after the marks have been marked on the tire. Therefore, if the marking device is not operating normally and faulty marks are formed on the tire, faulty marks will be formed on a plurality of tires before the faulty marks are found in the mark inspecting process, which reduces production efficiency.